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Henry77
 
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Default Blower on furnace hums and doesn't start


"Mark" wrote in message
om...
I am having problems with one of my two furnaces. When the thermostat
kicks in, the furnace will light, but the fan won't kick in. Then the
furnace shuts down. If I turn off the heat (i.e. not on heat or
cool), and turn the fan to "on", it just hums (the other furnace works
fine and the fan will run). There is a solenoid that clicks, then the
humming. The fan itself turns effortlessly.

Do you think this could be a problem with the capacitor, solenoid or
transformer?

Also, I have been having another problem (probably unrelated?) once a
year every winter when I first start the furnace. The fan doesn't
want to kick in but I didn't notice any humming - this appeared to
have something to do with that timer-like dial (is it a temperature
limit switch?). Two taps with the end of a screwdriver and I'm
usually OK for the year.

Any ideas on either problem? Thanks.


Too many variables to diagnose by remote control like does the blower
(fan) motor have a start cap , run cap , both or neither (blower motors can
be any of these). Could be a cap problem , relay problem , open start
winding or none of these -again depending on your equipment. The best bet is
call in an HVAC tech to take a look and I hope your not hitting the fan
limit switch with that hammer as it is also a safety device :-( .

Henry